Submarine mine.



A. E. T. BERGSTRUM;

' SUBMARINE MINE. APPLICATION FILEDUJULY 31, 1908.

wgiinessesj'nzin tm'" Patented Mar. 29,1910.

UNITED, sTArns PIENT oF Io AXEL- EDWIN THEoDoR-BERes'rnoM, OF STOCKHOLM, SWEDEN.

SUBMABINE MINE.

pApplicationfil ed July 31, 1908. Serial No. 446,244.

This invention relates to improvements in submarine n1ines;.--

The ob ect of the lnventlon is to enable mine's moored at comparatively large depths to automatically. disengage themselves and rise'toward the water surface, when an iron vessel-or a vessel made-of or containing a material adapted to influencea magnet"or the'like passes over or inthe vicinity of the minefurther object of the invention is to cause; the mine to. automatically explode, without shock, as soon as it has arrived sufficiently near the "water surface.

The invention consists, chiefly, in thatthe mine is provided with means adapted to re,

lease a catchy'when a vessel passes above or in the vicinity of the mine, so that the mine is'l'r'ee to ascendtoward the water surface.

The invention further comprises means for autoi'i'ia'tically exploding the mine, when it hasascended sufiiciently near the vessel, said means-suitably comprising a contact device included in the exploding circuit, one contact of said device being connected to the mooringbv a; line or the like of a suitable lengtlnso that, when the mine has ascended.

after release, to. a certain distance from the bottom, said contact brought into its cir;

cult-closing position and causes the mine to The invent on further comprises the constrtiiction and coi'ribination of parts herein after particularly described.

Themine is, suitably. moored at such a- ,depth that even the most deep-drawing vessels cannotstrike 'the mine, which 15 0t great importance during peace as well as during war, for instance 1n miningharbors or the like.' When using the systems of mining hitherto employed, there is great danger in touching at'such harbors, whereas; according to thej' present invention, thenaval commerce may freely proceed in spite of the mining.

In the drawing, I have shown a central vertical section of a mine embodying the invention.-

Referring to the drawing 1 is. the casing. of the mine. Placed centrally within the said casing is a tube 2, suitably of brass'or other non-magnetic material. Situated within the tube 2 is a movable core 30f softiron. Placed. above the said core, at the outer side of the tube -2, is a winding 4. hen the said winding is supplied. with current, it attracts the iron core 3 so that tained-in the position shown in the drawing by the weight of the iron core the lower end of "which is conical in shape. \Vhen the iron core is lifted, the hooks 6 spring inwardlvso 21 to disengage the flange 5, whereby the mine, on account of its floating l)O'\\'Ol',-tl5CQlitlS so far as the longer line 10 allows. The latter is shown attached, at its upper end. to a rod 11 thelike, s'aid rod passing water-tightly through the bottom of the mine casing and carrying, at its upper end; an insulating contactspring 12 held. b v a spring 13 ina raised position in which it is out of contact with the contact spring it. A sleeve 15 of india rubber Li'\'e to tighten against water without preventing the rod from moving longitudinally. When the mine has ascended so far as the longer line 10 allows. the rod 11 is retained while the body of the mine makes plied with current of a certain strength.

Specification of Letterslatent. P tented Mar. 29, 1910.

In order to enable ically disengage itself, when a vessel passes in the vicinity of the mine I provide two contact springs 19, 20 placed at an insulating' part 18 at the inner side of the mine casing. Suspended between the said springs is a magnetic needle 21 or the like, said needle being insulated and normally kept, by a spring (not shown) 'or otherwise, in

a ppsition in which it is out of contact wit the springs 19, 20. In the embodiment shown the needle is ofsoft iron and provided with windings whereby the needle is magnetized in such a manner that the ends thereof will be of opposite zpolarity. When a vessel passes over the mine, or in the vicinity thereof, the magnetic needle 21 is caused to take up the vertical position shown in the drawing in which it provides an electric connection between the contact s rings 19 and 20. Extended from lan or from another able place is an electric cable line 10 and passin into the mine 69.5111 One of the conducting wires 22 in the cable is connected to the contact spring 19, and another conducting wire 23 is connected to one end of the winding 4;,the other end of which is connected, by a conducting wire 24, to the contact spring 20. Leading from the conducting wire 22 is a conductor 25 spring 12, and leadsuitconnected tothe contact ing from the conducting wire 23 is a conductor 26 connected to one end of the fuse 17, the other'end of which is connected by a conductor 27 to the contact 14.

\Vhen a vessel passes over or in the vicinity of the mine, the magnetic needle 21 is attracted so as to take up the position. shown in the drawing in which it formsa bridge between the contacts 19- and 20. current is suppliedto the outer conductors,

it flows from the current source throughconductor 22, contact spring 19, magnetic needle 21, contact spring 20, conductor 24, winding 4, and conductor 23, back to the current source. On account thereof, the iron core 3 is attracted by the solenoid 4: so that the connecting part 7 is released and the mine ascends. \Vhen the mine has ascended so far as the line 10 allows, contact is made between the contact springs 12 and 14 by which a circuit is closed from the current source through conductors 22 and 25, sprin s 12 and 14:, conductor 27, fuse 17 and con rent source. The fuse is, thereby, caused to glow and ignite the dctonator. During the ascent of the mine, it moves toward the vessel on account of the magnetism of the core 3 so that explosion will take place close up to the vessel 'or as near, the same as possible.

In the. drawing,

the magnetic needle 21 the mine to automatfollowing the tion, a normally open i an iron vessel passes actors 26 and 23 back to the cur 1 has the form of a pm of soft iron surround- 1 ed by windings so that it may be magnetized by weak currents from and, but obviously a permanent magnet may be used, if desired. 1

It is obvious that the invention is not limited to the embodiment shown and described which may be varied in several ways without departing from the spirit of the invention.

Having now described my inventiomwhat I claim as new and desire to secure by Let ters Patent is:

1. The combination with a submarine mine, of a mooring, a catch=serving to nor} mally retain the m'ne in inoperative position, and means adapted to be operated by' an iron vessel passing in the vicinity of the mine.

The combination with a submarine mine, of a mooring, a catch serving to norimzinoperative posielectric circuit, a magnetically operated contact device included in the said electric circuit, said contact device being adapted to close the circuit, when in the vicinity of the l mine, and means controlled by the electric circuit for releasing the catch, when the electric circuit is closed.

3. The combination with a submarine mine, of a mooring, a catch serving to normally retain the mine ininoperative position, means for releasingthe catch adapted to be operated by an iron vessel passing in l the vicinity of the mine, and means for automatically exploding the mine, when it has ascended a predetermined distance.

4.. The combination with a submarine mine, of a mooring, a catch serving to nor mally retain the mine in inoperative position, means for releasing the catch adapted to be operated by an iron vessel passing in the vicinity of the mineya normally open electric circuit, means included in the said i circuit for exploding themine, when the circuit is closed, a contact device adapted l to close the said circuit, and a flexible connection between the mooring and the contact 1 device serving to close the latter, when the 1 mine has ascended to a position in which I the connection is stretched. The combination with a submarine mine, of a mooring, a catch serving to normaily retain the mine in ii'mpc ve posia normally open electric circuit, a netically operated contact device ini cluded in the said. electric circuit, said-con: i tact device being adapted to close the ciri cuit, when an iron vessel passes inthe vicinity of the mine, means controlled by the electric circuit for releasing the catch, when the electric circuit is closed, a normally open exploding circuit, means included in the mally retain the mine connection between the mooring and the said circuit ex'pimiiiigthe miiie; when In testimony whereof I have signed my the circuitismzlosed, aj ebntact device adaptria-meto this SPGQifiCfitiOILiil the presence of ed to close the said-.ciieuit, and a flexible two subscribing witnesses;

contact device serving to close the latter, I Witnesses:

-When the mine hasascended to a posit-ion- AUG. SiSRANSEN, in which the connection, is stretched. KARL RUNCSKOG.

AXEL EDWIN THEODOR BERGSTRUM. I 

